Average calculator



Aug- 2, 1955 A. F. s11 vANo AVERAGE CALCULATOR 2 Sheets-Sheet l Filed OC'C. 22, 1965 All@ 2 1956 A. F. SILyANo 3,263,919

AVERAGE CALCULATOR Filed Oct. 22, 1965 2Sheet$45heet 2 F l G. 3. 25

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INVENTOR.

A HON ESILVANO BY United States Patent() 3,263,919 AVERAGE CALCULATOR Anthony F. Silvano, 25 Chestnut St., West Springfield, Mass. rusa oct. 22, 1965, ser. N6. 500,685 4 Claims. (Cl. 23S- 70) The present invention relates to a calculating device of the anal-og type and more particularly to a calculating device useful in determining averages of 'a plurality of numbers, which averages can be read olf the device in the form of either a numerical or alphabetical grade.

By the use of the present invention, the often tedious and time consuming process of averaging a plurality of grades, scores, or the like is considerably simplified and inasmuch as such process is reduced to a simple mechanical operation, the opportunity of introducing error into such calculations is reduced.

-One object of this invention is to provi-de a slide rule Iwhich is readily manipulative for the purpose of determining `averages in a simple mechanical operation.

Another object is the provision of a slide rule which is simple and inexpensive in its construction, yet which is ideally suite-d for the purpose for which it is designed.

Additional objects `and advantages of the invention will become apparent during the course of the following specification when taken in connection with the accompanying drawings, in which:

FIG. 1 is a front elevation of a calculating slide rule in accordance with this invention.

FIG. 2 is a View showin-g, in unassembled form, the body of the slide rule of FIG. 1.,

FIG. 3 is a view showing, in unassembled form, the cursor of the slide rule of FIG. l.

lFIG. 3a is a side elevation of the cursor of FIG. 1; and

FIG. 4 is a front elevation view of the slide of FIG. 1.

yReferring to FIG. 1 the slide rule is composed of a body 1f1, a slide 12 and a hairline cursor 13. The body 11 may be constructed of ia blank of plastic or light metal, or any other suitable material and is provided with a plurality of scales as described hereinafter.

The blank 11, as shown in FIG. 2, is provided 'with a series of apertures y14, 15, 16, 17 and 18 and has a plurality of limit stops 19 and 20 thereon. Stop `19 projects outwardly from the face o-f the blank 11, While stop 20 projects from the rear side of such blank, and such stops may be formed integral with the blank 1|1 by means of any suitable punching or pressing opera-tion. The blank forming the body 11, after it is provided with the scales, apertures and stops above mentioned, is folded along the dotted lines 23, 24 to form an enclosure to receive the slide 12 therein.

The cursor 13 is made of -a somewhat flexible, transparent plastic type material and, as illustrated in FIG. 3, is a blank having a hairline 2S scribe-d or otherwise xed thereon. The cursor blank 13 is provided with a plurality of tabs 29, 60. Each of said tabs 29, 30 may be a simple indentation in the blank 13. Such indented portions of the cursor 13 may be provided with a frictional substance covering a portion 4of one side or both thereof, which frictional substance can take the form of, for example, a frictional coating applied thereto or, alternatively, a knurled surface scribed thereon.

The blank forming cursor 13, af-ter being constructed as shown in FIG. 3, is folded along the dotted lines 35, 36 to form a sleeve shaped cursor encircling the body 11, FIG. 1, in such a manner that it is freely slidable along the body y11 without engaging .the slide 12.

Referring to FIG. l, the scale 41 on slide 12 is divided into fifty equal units and is so placed on the slide that when the slide is at its leftmost position, engaging the left limit stop 20, the 100 unit mark on such scale will be 3,263,919 Patented August 2, 1966 visible 'through aperture 1'6 and aligned with the index mark 16a on body 1.1.

The scale 42 on body 11 is divided into one hundred equal units, each such unit being equal in length to onehalf of -a scale 41 unit. Similarly, scales 43 to 49 are each divided into one hundred units and each unit of lscales 43449 is equal in length to one-third to one-ninth, respectively, of a scale 41 unit.

The operation of the device is as follows, assuming that the average of four numerical values is desired. vIf it is desired to average the values eighty, forty, sixty and eighty, with the slide abutting stop 2li, the cursor is positioned with the hairline coincident with the unit mark on scale 44. The tabs 29 and 30` are then pressed against slide 12 and the cursor and the slide are moved away from stop 20, towards stop v19, until the cursor edge 21 abuts stop l19. Upon the completion of this opera-tion, the hairline Will be coincident with the 100 unit mark on scale 44 and the slide 12 will have -moved a distance, away from stop 20, equal -to twenty units of length on scale 44 or, since the units of scale 41 are four times the length of scale 44 units, a distance equ-al to iive scale 41 units. Thus, the u-nit mark of scale 41 will now be visible through the aperture .16.

The tabs 29 and 30 are now released from engaging relationship with the slide 12 and the hairline 25 is positioned over the forty unit mark of the `scale 44. The tabs are again pressed into engaging relationship with the slide 12 and the cursor and slide are moved towards the stop 19 until the cursor edge X211 again abuts said sto-p 19. Since during this second movement the slide 12 will have moved rightwardly a distance equal to the length of sixty scale -44 units or fifteen scale 41 units it Will be appreciated that the numeral eighty will now be visible through the aperture 16.

The above procedure is repeated for the two iinal grades to be averaged, i.e., sixty and eighty with the slide 12 moving rightwardly ten and ve scale 41 units each time. In consequence of the above mentioned steps the slide 12 will have moved rightwardly in increments of live, fifteen, ten and live units or a total of thirty-(tive, thus causing the sixty-five unit mar-k of s-cale 41, with its associated index niark, to appear in the aperture 16 in alignment with index mark 16a, sixty-iive being the correct average of the values eighty, forty, sixty and eighty.

If the average of three numbers is desired, say ninety, eighty, and seventy, the operation is as described above, but in this case the numbers to be averaged are located on the scale 43, that is, with the slide 12 .abutting the stop 20 the hairline 25 is located over the ninety index mark on scale 43 and the slide and cursor are moved rightwardly until the cursor 13 abuts `the stop 19. Then, in succeeding steps, the hairline is aligned with the eighty and seventy index marks of the scale 43 and the slide is similarly moved rightwards. Upon the complet-ion of these three steps, the slide will have moved rightwardly a distance equal to sixty scale 43 units or twenty scale 41 units yand the numeral 80 will appear in the aperture 14.

The sequence above described is likewisefollowed in averaging two, live, six, seven, eight or nine values using the -scales 42, 45, `46, 47, 48 or 49, respectively. Ten or more values may be averaged by breaking them into groups. For example, to average fifteen values, scale 47 is used for the lirst seven values, scale 48 is used for the remaining eight values, then scale 42 to average the two previously obtained averages.

Whether using the scales on the front or back of the assembled slide rule `of FIG. 1, they sequence is identical, that is, prior to setting up the -rst value on any scale 42-49 the slide is positioned in abutting relationship with stop 20 and in performing each step the cursor and slide are moved .along the body until the cursor edge 21 abuts 3 the stop 19. The numerical average will always appear in the aperture 16 located on the front of the rule, but of cou-rse, the reverse side of the slide 12 may have the scale 41 suitably indicated thereon so that the average gure will likewise always appear in the aperture 14.

The slide 12 may also have imprinted or scribed thereon an alphabet-ical scale 54 divide dinto alphabetically designated zones such as an A zone, a B zone, `a C zone, a D Zone and lan F zone. The zones may be indicated by locating the alphabetical characters thereon, as shown in FIG. 4, or -such zones could be indicated by a color code running through their length. In either case, an alphabetical average will be caused to appear ythrough the apertures 15 and 17 simultaneously with the appearance of the aforementioned numerical average in apertures 14 and 16.

Additionally, although I have shown the scale 41 as hav-ing only fifty units, it is obvious that such 4scale could be provided with one hundred such units to make it possible to obtain averages of less than fifty.

Having thus described my invention, I claim:

1. A slide rule calculating device having `a slide receiving body, a plurality lof apertures formed in said body, a slide, said slide movable to and fro within, and along the longitudinal axis of, said body, a cursor movable to and fro along said body, said slide having a rst scale thereon, said body having a plurality of scales thereon, each of said scales being divided along its length in-to a plurality of units, the length of each of the units of said plurality of scales being an aliquot portion of the length of each unit on said slide, said slide being engageable by said cursor for movement simultaneously with said cursor to cause segments of said scale on said slide to be exposed through at least one of said apertures.

2. The invention of claim 1 wherein said cursor has formed thereon a plurali/ty of depressed areas.

3. The invention of claim 1 wherein said slide is provided with a second scale, portions of which may be selectively exposed through another of said apertures.

4. The invention of claim 2 wherein said depressed surfaces are engageable with said slide to frictionally bear thereagainst for simultaneous movement of said slide and said cur-sor.

References Cited by the Examiner UNITED STATES PATENTS 1,461,975 7/1923 Eaton et al. 23S-70.2 2,277,993 3/ 1942 Preston 23S- 69 3,002,683 10/1961 Rowland 23S-88 FOREIGN PATENTS 400,850 8/ 1924 Germany.

LOUIS I. CAPOZI, Primary Examiner. 

1. A SLIDE RULE CALCULATING DEVICE HAVING A SLIDE RECEIVING BODY, A PLURALITY OF APERTURES FORMED IN SAID BODY, A SLIDE, SAID SLIDE MOVABLE TO AND FRO WITHIN, SAID ALONG THE LONGITUDINAL AXIS OF, SAID BODY, A CURSOR MOVABLE TO AND FRO ALONG SAID BODY, SAID SLIDE HAVING A FIRST SCALE THEREON, SAID BODY HAVING A PLURALITY OF SCALES THEREON, EACH OF SAID SCALES BEING DIVIDED ALONG ITS LENGTH INTO A PLURALITY OF UNITS, THE LENGTH OF EACH OF THE UNITS OF SAID PLURALITY OF SCALES BEING AN ALIQUOT PORTION OF THE LENGTH OF EACH UNIT ON SAID SLIDE, SAID SLIDE BEING ENGAGEABLE BY SAID CURSOR FOR MOVEMENT SIMULTANEOUSLY WITH SAID CURSOR TO CAUSE SEGMENTS OF SAID SCALE ON SAID SLIDE TO BE EXPOSED THROUGH AT LEAST ONE OF SAID APERTURES. 